Why does my output of my PI controller is always zero

Hi i am currently doing a v2g bidirectional application.

My PI controller output consistenly give me zero output despite changing the P and I gain of the controller anyone knows how to solve this issue. It is urgent as i am doing my final year project in college.

Thanks alot in advance

Some background information this is the control for my buck-boost bidirectional converter. im using a capacitor (DC Link) as my V load to be as reference when v2g and

using battery voltage for g2v. im using soc to determine the 3 phase bridge be as rectifier mode or inverter mode for my v2g or g2v application, it will produde a '1' or '0' respectively